Autoimmune disease results when a subject's immune system attacks its own tissues often resulting in severe morbidity or death. Examples of such diseases include type 1 insulin dependent diabetes, multiple sclerosis, rheumatoid arthritis and inflammatory bowel disease.
The immune system also can cause illness as a consequence of its reaction to a transplanted organ, tissue or cell, where the organ, tissue or cell is recognized as foreign. Typically the transplanted organ or tissue is recognized as foreign by the host and infiltrated by the host immune cells, which then carry out their effector function and destroy the transplant. Typical treatments to help suppress the immune response that is elicited by foreign transplant include immunosupressive drugs such as corticosteroids, cyclosporin A, rapamycin and FK506 or antibody therapies such as anti T-cell antibodies. These therapies are not specific and typically must be administered for the life of the patient. Additionally, these therapies have undesirable side effects such as high blood pressure, renal failure, lowered resistance to infection and fever. The costs of those treatments over a lifetime is also quite expensive.
In response to the aforementioned problems associated with immunosupression therapies, there exists a clear need for more efficacious and less problematic therapies to treat autoimmune diseases and organ or tissue rejection.